Running Pandoc on a selection within a file in Vim

Vim is great for editing markdown, but there still seem to be occasions where macros and other tricks are not quite enough. Markdown tables are a perfect example. Vim's block selector and substitution commands are a big help, but sometimes you just want to reformat the whole table in one command.

In such cases, you can run Pandoc on a visual mode selection converting only a part of the file. Suppose you have the following table:

| Column A | Column B | Column C |
|----------|----------|----------|
| Data 1   | Stuff    | Things   |
| Data 2   | More     | Whatever |
| Meh      | IDK      | ¯\_(ツ)_/¯ |
| Yep      | Lazy     | Didn't even align this |
| ???      | ...      | Table auto-generated probably |

You could select this table in visual mode and then run this command:

:'<,'>! pandoc -t markdown_strict+grid_tables

:'<,'>! runs a shell command, passing the selection as standard input.
-t markdown_strict+grid_tables sets the output format to markdown with grid tables.¹

Here is the result:

+----------+----------+-------------------------------+
| Column A | Column B | Column C                      |
+==========+==========+===============================+
| Data 1   | Stuff    | Things                        |
+----------+----------+-------------------------------+
| Data 2   | More     | Whatever                      |
+----------+----------+-------------------------------+
| Meh      | IDK      | ¯\_(ツ)\_/¯                   |
+----------+----------+-------------------------------+
| Yep      | Lazy     | Didn’t even align this        |
+----------+----------+-------------------------------+
| ???      | …        | Table auto-generated probably |
+----------+----------+-------------------------------+

Footnotes:

markdown_strict is necessary because of the way Pandoc handles table styles. references/pandoc-table-support-is-inclusive.html